268 research outputs found
A Tribute to Thomas M. Church: Exploring Chemical Oceanography in the Coastal Zone-The History and Future
( First paragraph) One can find different historical perspectives on the development of studying the chemistry of oceans as well as names for this studyâmarine chemistry, chemistry of the sea, marine aquatic chemistry, marine biogeochemistry, or chemical oceanography. It could be argued that chemical oceanography is the most inclusive for an earth science since oceanography itself is an integrated discipline that links the biology, chemistry, geology, and physics together. Regardless of the name, perhaps the first intensive, modern/post-nineteenth century study of the oceanâs chemistry was the GEOSECS Program from ca. 1970â1978. The significance of GEOSECS was that it examined the chemistry of the worldâs oceans from nutrients to radionuclides, and even a few trace elements, but in a physical context of ocean circulation (e.g., Craig 1972). Thomas M. Church (Figs. 1 and 2) was ââbornââ into the GEOSECS world, receiving his Ph.D. in 1970 from Scripps Institution of Oceanography in the laboratory of Edward Goldberg with the first examination of marine barite in the worldâs oceans. GEOSECS was a ââblue waterââ program, but Tom Church decided to take the road less travelled at the time to examine chemical processes in the coastal zone. The coastal zone has been described, both then and now and always somewhat facetiously, as the ââbrown ring around the bathtub,ââ but many would argue that this minimizes its importance since it is here where continental weathering products are primarily introduced to the ocean and where many of these same products are also removed. Primary productivity is at a maximum in coastal waters, and human populations and effects are also concentrated here
Distributions and abundances of Pacific sardine (Sardinops sagax) and other pelagic fishes in the California Current Ecosystem during spring 2006, 2008, and 2010, estimated from acousticâtrawl surveys
The abundances and distributions of coastal pelagic fish
species in the California Current Ecosystem from San Diego to southern Vancouver Island, were estimated from combined acoustic and trawl surveys conducted in the spring of 2006, 2008, and 2010. Pacific sardine (Sardinops sagax), jack mackerel (Trachurus symmetricus), and Pacific mackerel (Scomber japonicus) were the dominant coastal pelagic fish species, in that order. Northern anchovy (Engraulis mordax) and Pacific herring (Clupea pallasii) were sampled only sporadically and therefore estimates for these species were
unreliable. The estimates of sardine biomass compared well with those of the annual assessments and confirmed a declining trajectory of the ânorthern stockâ since 2006. During the sampling period, the biomass of jack mackerel was stable or increasing, and that of Pacific mackerel was
low and variable. The uncertainties in these estimates are mostly the result of spatial patchiness which increased
from sardine to mackerels to anchovy and herring. Future surveys of coastal pelagic fish species in the California
Current Ecosystem should benefit from adaptive sampling based on modeled habitat; increased echosounder and trawl sampling, particularly for the most patchy and nearshore species; and directed-trawl sampling for improved species identification and estimations of their acoustic target
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Evidence for donor strand complementation in the biogenesis of Haemophilus influenzae haemagglutinating pili
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73758/1/j.1365-2958.2000.01816.x.pd
Risk of cerebrovascular disease among 13,457 fiveâyear survivors of childhood cancer: a population based cohort study
Survivors of childhood cancer treated with cranial irradiation are at risk of cerebrovascular disease (CVD), but the risks beyond age 50 are unknown. In all, 13457 survivors of childhood cancer included in the populationâbased British Childhood Cancer Survivor Study cohort were linked to Hospital Episode Statistics data for England. Risk of CVD related hospitalisation was quantified by standardised hospitalisation ratios (SHRs), absolute excess risks and cumulative incidence. Overall, 315 (2.3%) survivors had been hospitalised at least once for CVD with a 4âfold risk compared to that expected (95% confidence interval [CI]: 3.7â4.3). Survivors of a central nervous system (CNS) tumour and leukaemia treated with cranial irradiation were at greatest risk of CVD (SHR = 15.6, 95% CI: 14.0â17.4; SHR = 5.4; 95% CI: 4.5â6.5, respectively). Beyond age 60, on average, 3.1% of CNS tumour survivors treated with cranial irradiation were hospitalised annually for CVD (0.4% general population). Cumulative incidence of CVD increased from 16.0% at age 50 to 26.0% at age 65 (general population: 1.4â4.2%). In conclusion, among CNS tumour survivors treated with cranial irradiation, the risk of CVD continues to increase substantially beyond age 50 up to at least age 65. Such survivors should be: counselled regarding this risk; regularly monitored for hypertension, dyslipidaemia and diabetes; advised on lifeâstyle risk behaviours. Future research should include the recall for counselling and brain MRI to identify subgroups that could benefit from pharmacological or surgical intervention and establishment of a caseâcontrol study to comprehensively determine riskâfactors for CVD
Outcomes and risk factors associated with SARS-CoV-2 infection in a North American registry of patients with multiple sclerosis
Importance: Emergence of SARS-CoV-2 causing COVID-19 prompted the need to gather information on clinical outcomes and risk factors associated with morbidity and mortality in patients with multiple sclerosis (MS) and concomitant SARS-CoV-2 infections.
Objective: To examine outcomes and risk factors associated with COVID-19 clinical severity in a large, diverse cohort of North American patients with MS.
Design, Setting, and Participants: This analysis used deidentified, cross-sectional data on patients with MS and SARS-CoV-2 infection reported by health care professionals in North American academic and community practices between April 1, 2020, and December 12, 2020, in the COVID-19 Infections in MS Registry. Health care professionals were asked to report patients after a minimum of 7 days from initial symptom onset and after sufficient time had passed to observe the COVID-19 disease course through resolution of acute illness or death. Data collection began April 1, 2020, and is ongoing.
Exposures: Laboratory-positive SARS-CoV-2 infection or highly suspected COVID-19.
Main Outcomes and Measures: Clinical outcome with 4 levels of increasing severity: not hospitalized, hospitalization only, admission to the intensive care unit and/or required ventilator support, and death.
Results: Of 1626 patients, most had laboratory-positive SARS-CoV-2 infection (1345 [82.7%]), were female (1202 [74.0%]), and had relapsing-remitting MS (1255 [80.4%]). A total of 996 patients (61.5%) were non-Hispanic White, 337 (20.8%) were Black, and 190 (11.7%) were Hispanic/Latinx. The mean (SD) age was 47.7 (13.2) years, and 797 (49.5%) had 1 or more comorbidity. The overall mortality rate was 3.3% (95% CI, 2.5%-4.3%). Ambulatory disability and older age were each independently associated with increased odds of all clinical severity levels compared with those not hospitalized after adjusting for other risk factors (nonambulatory: hospitalization only, odds ratio [OR],â2.8 [95% CI, 1.6-4.8]; intensive care unit/required ventilator support, OR,â3.5 [95% CI, 1.6-7.8]; death, OR,â25.4 [95% CI, 9.3-69.1]; age [every 10 years]: hospitalization only, OR,â1.3 [95% CI, 1.1-1.6]; intensive care unit/required ventilator support, OR,â1.3 [95% CI, 0.99-1.7]; death, OR, 1.8 [95% CI, 1.2-2.6]).
Conclusions and Relevance: In this registry-based cross-sectional study, increased disability was independently associated with worse clinical severity including death from COVID-19. Other risk factors for worse outcomes included older age, Black race, cardiovascular comorbidities, and recent treatment with corticosteroids. Knowledge of these risk factors may improve the treatment of patients with MS and COVID-19 by helping clinicians identify patients requiring more intense monitoring or COVID-19 treatment
Cardiac structure doses in women irradiated for breast cancer in the past and their use in epidemiological studies
Risk of heart failure in survivors of Hodgkin lymphoma: Effects of cardiac exposure to radiation and anthracyclines
Hodgkin lymphoma (HL) survivors treated with radiotherapy and/or chemotherapy are known to have increased risks of heart failure (HF), but a radiation dose-response relationship has not previously been derived. A case-control study, nested in a cohort of 2617 five-year survivors of HL diagnosed before age 51 years during 1965 to 1995, was conducted. Cases (n 5 91) had moderate or severe HF as their first cardiovascular diagnosis. Controls (n 5 278) were matched to cases on age, sex, and HL diagnosis date. Treatment and follow-up information were abstracted from medical records. Mean heart doses and mean left ventricular doses (MLVD) were estimated by reconstruction of individual treatments on representative computed tomography datasets. Average MLVD was 16.7 Gy for cases and 13.8 Gy for controls (Pdifference 5 .003). HF rate increased with MLVD: relative to 0 Gy, HF rates following MVLD of 1-15, 16-20, 21-25, and â„26 Gy were 1.27, 1.65, 3.84, and 4.39, respectively (Ptrend < .001). Anthracycline-containing chemotherapy increased HF rate by a factor of 2.83 (95% CI: 1.43-5.59), and there was no significant interaction with MLVD (Pinteraction 5 .09). Twenty-fiveâyear cumulative risks of HF following MLVDs of 0-15 Gy, 16-20 Gy, and â„21 Gy were 4.4%, 6.2%, and 13.3%, respectively, in patients treated without anthracycline-containing chemotherapy, and 11.2%, 15.9%, and 32.9%, respectively, in patients treated with anthracyclines. We have derived quantitative estimates of HF risk in patients treated for HL following radiotherapy with or without anthracycline-containing chemotherapy. Our results enable estimation of HF risk for patients before treatment, during radiotherapy planning, and during follow-up
Prediction and confirmation of seasonal migration of Pacific sardine (Sardinops sagax) in the California Current Ecosystem
During the last century, the population of Pacific sardine
(Sardinops sagax) in the California Current Ecosystem has exhibited large fluctuations in abundance and migration behavior. From approximately 1900 to 1940, the abundance
of sardine reached 3.6 million metric tons and the ânorthern stockâ migrated from offshore of California
in the spring to the coastal areas near Oregon, Washington, and Vancouver Island in the summer. In the 1940s, the sardine stock collapsed and the few remaining sardine schools concentrated in the coastal region off southern California, year-round, for the next 50 years. The stock gradually recovered in the late 1980s and resumed its seasonal migration between regions off southern California and Canada. Recently, a model was developed which predicts
the potential habitat for the northern stock of Pacific sardine and its seasonal dynamics. The habitat predictions were successfully validated using data from sardine surveys
using the daily egg production method; scientific trawl surveys off the Columbia River mouth; and commercial sardine landings off Oregon, Washington, and Vancouver Island. Here, the predictions of the potential habitat and seasonal migration of the northern stock of sardine are
validated using data from âacousticâtrawlâ surveys of the entire west coast of the United States during the spring
and summer of 2008. The estimates of sardine biomass and lengths from the two surveys are not significantly
different between spring and summer, indicating that they are representative of the entire stock. The results
also confirm that the model of potential sardine habitat can be used to optimally apply survey effort and thus minimize random and systematic sampling error in the biomass
estimates. Furthermore, the acousticâtrawl survey data are useful to estimate concurrently the distributions and abundances of other pelagic fishes
Atmospheric hydrogen sulfide over the equatorial Pacific (SAGA 3)
Atmospheric H2S concentrations were measured over the equatorial Pacific on leg 1 of the third Soviet-American Gases and Aerosols (SAGA 3) cruise during February and March 1990. Five N-S transects were made across the equator between Hawaii and American Samoa. The concentrations ranged from below the detection limit of 0.4 ± 0.5 (1 Ï) to 14.4 ppt with an average value of 3.6 ± 2.3 ppt (1Ï, n= 72). The highest concentrations were found on the easternmost two transects just south of the equator. The average concentration of 3.6 ppt observed on this cruise is the lowest reported value for background atmospheric H2S over the tropical oceans. A lack of correlation between 222Rn and H2S rules out a significant continental source. Model calculations indicate that the oceanic source of H2S in this region is in the range of 9 to 21 Ă 10â8 mol mâ2 dâ1. From this flux the concentration of free sulfide (H2S + S= ) in the surface mixed layer of the ocean is estimated to be in the range of 32 to 67 pmol Lâ1. In the atmosphere the oxidation of H2S produces SO2 at a rate of 2.1 to 4.4 Ă 10â11 mol mâ3 dâ1 which is only a small fraction of that estimated from the oxidation of dimethyl sulfide (DMS) in this region. A diurnal cycle was not observed in the H2S data recorded during this cruise
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